Schizophrenia and epilepsy: is there a shared susceptibility?

Individuals with epilepsy are at increased risk of having psychotic symptoms that resemble those of schizophrenia. More controversial and less searched is if schizophrenia is a risk factor for epilepsy. Here we review overlapping epidemiological, clinical, neuropathological and neuroimaging features of these two diseases. We discuss the role of temporal and other brain areas in the development of schizophrenia-like psychosis of epilepsy. We underline the importance of ventricular enlargement in both conditions as a phenotypic manifestation of a shared biologic liability that might relate to abnormalities in neurodevelopment. We suggest that genes implicated in neurodevelopment may play a common role in both conditions and speculate that recently identified causative genes for partial complex seizures with auditory features might help explain the pathophysiology of schizophrenia. These particularly include the leucine-rich glioma inactivated (LGI) family gene loci overlap with genes of interest for psychiatric diseases like schizophrenia. Finally, we conclude that LGI genes associated with partial epilepsy with auditory features might also represent genes of interest for schizophrenia, especially among patients with prominent auditory hallucinations and formal thought disorder.